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Results for "Kshitij Dwivedi"

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Deep Anchored Convolutional Neural NetworksApr 22 2019Convolutional Neural Networks (CNNs) have been proven to be extremely successful at solving computer vision tasks. State-of-the-art methods favor such deep network architectures for its accuracy performance, with the cost of having massive number of parameters ... More
Representation Similarity Analysis for Efficient Task taxonomy & Transfer LearningApr 26 2019Transfer learning is widely used in deep neural network models when there are few labeled examples available. The common approach is to take a pre-trained network in a similar task and finetune the model parameters. This is usually done blindly without ... More
The Algonauts Project: A Platform for Communication between the Sciences of Biological and Artificial IntelligenceMay 14 2019In the last decade, artificial intelligence (AI) models inspired by the brain have made unprecedented progress in performing real-world perceptual tasks like object classification and speech recognition. Recently, researchers of natural intelligence have ... More
Hands-on Experience with Gaussian Processes (GPs): Implementing GPs in Python - ISep 06 2018This document serves to complement our website which was developed with the aim of exposing the students to Gaussian Processes (GPs). GPs are non-parametric Bayesian regression models that are largely used by statisticians and geospatial data scientists ... More
Embedding and partial resolution of complex cones over Fano threefoldsMay 23 2015Oct 03 2016This work deals with the study of embeddings of toric Calabi-Yau fourfolds which are complex cones over the smooth Fano threefolds. In particular, we focus on finding various embeddings of Fano threefolds inside other Fano threefolds and study the partial ... More
Picone's Identity for $p$-biharmonic operator and Its ApplicationsMar 18 2015Apr 02 2015In this article we prove the nonlinear analogue of Picone's identity for $p-$biharmonic operator. As an application of our result we show that the Morse index of the zero solution to a $p-$biharmonic boundary value problem is $0$. We also prove a Hardy ... More
Wishart distributions for decomposable covariance graph modelsMar 09 2011Gaussian covariance graph models encode marginal independence among the components of a multivariate random vector by means of a graph $G$. These models are distinctly different from the traditional concentration graph models (often also referred to as ... More
Consistent estimation of the spectrum of trace class data augmentation algorithmsNov 02 2017Nov 29 2017Markov chain Monte Carlo is widely used in a variety of scientific applications to generate approximate samples from intractable distributions. A thorough understanding of the convergence and mixing properties of these Markov chains can be obtained by ... More
Convergence analysis of some multivariate Markov chains using stochastic monotonicityFeb 22 2013We provide a nonasymptotic analysis of convergence to stationarity for a collection of Markov chains on multivariate state spaces, from arbitrary starting points, thereby generalizing results in [Khare and Zhou Ann. Appl. Probab. 19 (2009) 737-777]. Our ... More
Convergence properties of Gibbs samplers for Bayesian probit regression with proper priorsFeb 27 2016Mar 05 2016The Bayesian probit regression model (Albert and Chib (1993)) is popular and widely used for binary regression. While the improper flat prior for the regression coefficients is an appropriate choice in the absence of any prior information, a proper normal ... More
Research News -- Quantum Mechanical Entanglement and Tests of CPT Theorem with Neutral Mesons at e+ e- CollidersSep 02 2007We review the recent confirmation of quantum entanglement in e+ e- collisions at the BELLE experiment at KEK-B in Japan with neutral B- mesons, and at the KLOE experiment at the DAFNE in Italy with neutral K- mesons. Such effects in the latter system ... More
Convergence properties of Gibbs samplers for Bayesian probit regression with proper priorsFeb 27 2016Jan 03 2017The Bayesian probit regression model (Albert and Chib (1993)) is popular and widely used for binary regression. While the improper flat prior for the regression coefficients is an appropriate choice in the absence of any prior information, a proper normal ... More
Rates of convergence of some multivariate Markov chains with polynomial eigenfunctionsJun 23 2009We provide a sharp nonasymptotic analysis of the rates of convergence for some standard multivariate Markov chains using spectral techniques. All chains under consideration have multivariate orthogonal polynomial as eigenfunctions. Our examples include ... More
Sparse Matrix Decompositions and Graph CharacterizationsNov 28 2011Mar 22 2012The question of when zeros (i.e., sparsity) in a positive definite matrix $A$ are preserved in its Cholesky decomposition, and vice versa, was addressed by Paulsen et al. in the Journal of Functional Analysis (85, pp151-178). In particular, they prove ... More
Equilibration problem for the generalized Langevin equationApr 06 2006Aug 24 2007We consider the problem of equilibration of a single oscillator system with dynamics given by the generalized Langevin equation. It is well-known that this dynamics can be obtained if one considers a model where the single oscillator is coupled to an ... More
Convergence of cyclic coordinatewise l1 minimizationApr 21 2014Jan 29 2015We consider the general problem of minimizing an objective function which is the sum of a convex function (not strictly convex) and absolute values of a subset of variables (or equivalently the l1-norm of the variables). This problem appears exten- sively ... More
Communication trade-offs for synchronized distributed SGD with large step sizeApr 25 2019Synchronous mini-batch SGD is state-of-the-art for large-scale distributed machine learning. However, in practice, its convergence is bottlenecked by slow communication rounds between worker nodes. A natural solution to reduce communication is to use ... More
Adaptive Scheduling in Real-Time Systems Through Period AdjustmentDec 14 2012Real time system technology traditionally developed for safety critical systems, has now been extended to support multimedia systems and virtual reality. A large number of real-time application, related to multimedia and adaptive control system, require ... More
Inverse algorithm and M2-brane theoriesAug 11 2011Nov 01 2011Recent paper arXiv:1103.0553 studied the quiver gauge theories on coincident $M2$ branes on a singular toric Calabi-Yau 4-folds which are complex cone over toric Fano 3-folds. There are 18 toric Fano manifolds but only 14 toric Fano were obtained from ... More
Naked Singularity, Black-hole and the Mass Loss in a Spherically Symmetric Gravitational CollapseNov 07 2001A distinguishable physical property between a naked singularity and a black-hole, formed during a gravitational collapse has important implications for both experimental and theoretical relativity. We examine the energy radiated during the spherically ... More
Some remarks on the qualitative questions for biharmonic equationsDec 21 2013Mar 19 2014In this article, we obtain several interesting remarks on the qualitative questions such as stability criteria, Morse index, Picone's identity for biharmonic equations.
An Efficient Multiplication Algorithm Using Nikhilam MethodJul 10 2013Multiplication is one of the most important operation in computer arithmetic. Many integer operations such as squaring, division and computing reciprocal require same order of time as multiplication whereas some other operations such as computing GCD ... More
Simple 8085 microprocessor compatible I/O cardOct 19 2004A simple interfacing project with the 8085-microprocessor kits available in under graduate college labs has been discussed. The interface card to study the I-V characteristics of a p-n diode emphasizes how the microprocessor can be used to do experiments ... More
A Classical Version of the Non-Abelian Gauge AnomalyMay 08 2013Aug 16 2013We show that a version of the covariant gauge anomaly for a 3+1 dimensional chiral fermion interacting with a non-Abelian gauge field can be obtained from the classical Hamiltonian flow of its probability distribution in phase space. The only quantum ... More
Stability of positive solutions to biharmonic equations on Heisenberg groupJun 21 2016Sep 06 2016In this note, we establish the existence of a positive solution and its stability to the following problem $$\Delta_{\mathbb{H}^n}^2u=a(\xi)u-f(\xi,u)\text{ in }\Omega, \,\,\, u|_{\partial\Omega} = 0 =\left.\Delta_{\mathbb{H}^n} u|_{\partial\Omega},$$ ... More
A non-invertible cancelable fingerprint template generation based on ridge feature transformationMay 28 2018In a biometric verification system, leakage of biometric data leads to permanent identity loss since original biometric data is inherently linked to a user. Further, various types of attacks on a biometric system may reveal the original template and utility ... More
Significant Results from SUMER/SOHONov 08 2006We briefly outline recent observations by solar spacecraft such as Yohkoh, SOHO, TRACE, and RHESSI, which have revolutionized what we know and don't know about the Sun. We then present some significant results, mainly from SUMER/SOHO but also complimentary ... More
Singular Adams inequality for biharmonic operator on Heisenberg Group and its applicationsJun 21 2016The goal of this paper is to establish singular Adams type inequality for biharmonic operator on Heisenberg group. As an application, we establish the existence of a solution to \begin{equation*} \Delta_{\mathbb{H}^n}^2 u=\frac{f(\xi,u)}{\rho(\xi)^a}\,\,\text{ ... More
A novel hybrid score level and decision level fusion scheme for cancelable multi-biometric verificationMay 26 2018In spite of the benefits of biometric-based authentication systems, there are few concerns raised because of the sensitivity of biometric data to outliers, low performance caused due to intra-class variations and privacy invasion caused by information ... More
Computing Multiplicative Order and Primitive Root in Finite Cyclic GroupAug 21 2014Multiplicative order of an element $a$ of group $G$ is the least positive integer $n$ such that $a^n=e$, where $e$ is the identity element of $G$. If the order of an element is equal to $|G|$, it is called generator or primitive root. This paper describes ... More
Is toric duality a Seiberg-like duality in (2+1)-d ?Jan 13 2014Jun 27 2014We show that not all $(2+1)$ dimensional toric phases are Seiberg-like duals. Particularly, we work out superconformal indices for the toric phases of Fanos ${\cal{C}}_3$, ${\cal{C}}_5$ and ${\cal{B}}_2$. We find that the indices for the two toric phases ... More
Classical chiral kinetic theory and anomalies in even space-time dimensionsAug 21 2013We propose a classical action for the motion of massless Weyl fermions in a background gauge field in (2N+1)+1 spacetime dimensions. We use this action to derive the collisionless Boltzmann equation for a gas of such particles, and show how classical ... More
Field of a Radiation DistributuionOct 12 1997Jun 20 1998General relativistic spherically symmetric matter field with a vanishing stress energy scalar is analyzed. Procedure for generating exact solutions of the field equations for such matter distributions is given. It is further pointed out that all such ... More
Stability of positive solutions to biharmonic equations on Heisenberg groupJun 21 2016Apr 27 2019In this note, we establish the existence of a positive solution and its stability to the following problem $$\Delta_{\mathbb{H}^n}^2u=a(\xi)u-f(\xi,u)\text{ in }\Omega, \,\,\, u|_{\partial\Omega} = 0 =\left.\Delta_{\mathbb{H}^n} u|_{\partial\Omega},$$ ... More
Phase Space Entanglement SpectrumFeb 26 2018We generalize the position- and momentum-space entanglement cuts to a family of cuts corresponding to regions in the classical phase space. We explicitly compute the entanglement spectra of free fermionic many-body wavefunctions for a family of phase ... More
Of Bulk and Boundaries: Generalized Transfer Matrices for Tight-Binding ModelsOct 14 2015Apr 08 2016We construct a generalized transfer matrix corresponding to noninteracting tight-binding lattice models, which can subsequently be used to compute the bulk bands as well as the edge states. Crucially, our formalism works even in cases where the hopping ... More
Partial resolution of complex cones over Fano ${\cal{B}}$Jun 16 2012Oct 23 2013In our recent paper arXiv:1108.2387, we systematized inverse algorithm to obtain quiver gauge theory living on the M2-branes probing the singularities of special kind of Calabi-Yau four-folds which were complex cones over toric Fano $\mathbb{P}^3$, ${\cal{B}}_1$, ... More
GCD Computation of n IntegersJul 25 2014Greatest Common Divisor (GCD) computation is one of the most important operation of algorithmic number theory. In this paper we present the algorithms for GCD computation of $n$ integers. We extend the Euclid's algorithm and binary GCD algorithm to compute ... More
Geometric responses of the Pfaffian stateFeb 25 2019We define and study the Pfaffian state on Riemann surfaces with arbitrary metrics and an inhomogeneous magnetic field and derive its universal transport coefficients. Following a path integral approach, we compute the effective action in terms of the ... More
Photon redshift and the appearance of a naked singularityMay 09 1998May 28 1998In this paper we analyze the redshift as observed by an external observer receiving photons which terminate in the past at the naked singularity formed in a Tolman-Bondi dust collapse. Within the context of models considered here it is shown that photons ... More
Generating protected fingerprint template utilizing coprime mapping transformationMay 25 2018The identity of a user is permanently lost if biometric data gets compromised since the biometric information is irreplaceable and irrevocable. To revoke and reissue a new template in place of the compromised biometric template, the idea of cancelable ... More
Necessary and Sufficient Conditions for High-Dimensional Posterior Consistency under $g$-PriorsSep 03 2015We examine necessary and sufficient conditions for posterior consistency under $g$-priors, including extensions to hierarchical and empirical Bayesian models. The key features of this article are that we allow the number of regressors to grow at the same ... More
Estimating Achievable Range of Ground Robots Operating on Single Battery Discharge for Operational Efficacy AmeliorationNov 07 2018Mobile robots are increasingly being used to assist with active pursuit and law enforcement. One major limitation for such missions is the resource (battery) allocated to the robot. Factors like nature and agility of evader, terrain over which pursuit ... More
Emergence of (bi)multi-partiteness in networks having inhibitory and excitatory couplingsApr 03 2015Jul 15 2015(Bi)multi-partite interaction patterns are commonly observed in real world systems which have inhibitory and excitatory couplings. We hypothesize these structural interaction pattern to be stable and naturally arising in the course of evolution. We demonstrate ... More
Influence of electronic structure parameters on the electrical transport and magnetic properties of $Y_{2-x}Bi_xIr_2O_7$ pyrochlore iridatesMay 07 2019We report the systematic study of structural, magnetic and electrical transport properties of $Y_{2-x}Bi_xIr_2O_7$ (x = 0.0, 0.1, 0.2, 0.3) pyrochlore iridates. The chemical doping enhances electrical conductivity and antiferromagnetic correlation substantially. ... More
Coexistence of high electrical conductivity and weak ferromagnetism in Cr doped Y$_2$Ir$_2$O$_7$ pyrochlore iridateApr 11 2019We report the structural, magnetic and electrical transport properties of Y$_2$Ir$_{2-x}$Cr$_x$O$_7$ pyrochlore iridates. The chemical doping leads to order of magnitude enhancement of electrical conductivity. The introduction of Cr3+ at Ir4+ site tends ... More
Photon in a cavity -- a GedankenexperimentJul 09 2013The inertial and gravitational mass of electromagnetic radiation (i.e., a photon distribution) in a cavity with reflecting walls has been treated by many authors for over a century. After many contending discussions, a consensus has emerged that the mass ... More
Solar coronal plumes and the fast solar windJan 08 2015The spectral profiles of the coronal Ne viii line at 77 nm have different shapes in quiet-Sun regions and coronal holes (CHs). A single Gaussian fit of the line profile provides an adequate approximation in quiet-Sun areas, whereas a strong shoulder on ... More
On the potential energy in a gravitationally bound two-body system with arbitrary mass distributionFeb 12 2015The potential energy problem in a gravitationally bound two-body system has recently been studied in the framework of a proposed impact model of gravitation (Wilhelm and Dwivedi 2015). The result was applied to the free fall of the so-called Mintrop--Ball ... More
On the potential energy in an electrostatically bound two-body systemAug 30 2014The potential energy problem in an electrostatically bound two-body system is studied in the framework of a recently proposed impact model of the electrostatic force and in analogy to the potential energy in a gravitationally bound system. The physical ... More
Balanced condition in networks leads to Weibull statisticsNov 27 2013The importance of the balance in inhibitory and excitatory couplings in the brain has increasingly been realized. Despite the key role played by inhibitory-excitatory couplings in the functioning of brain networks, the impact of a balanced condition on ... More
Extreme-value statistics of networks with inhibitory and excitatory couplingsApr 27 2013Inspired by the importance of inhibitory and excitatory couplings in the brain, we analyze the largest eigenvalue statistics of random networks incorporating such features. We find that the largest real part of eigenvalues of a network, which accounts ... More
A test for second order stationarity of a time series based on the Discrete Fourier Transform (Technical Report)Nov 25 2009We consider a zero mean discrete time series, and define its discrete Fourier transform at the canonical frequencies. It is well known that the discrete Fourier transform is asymptotically uncorrelated at the canonical frequencies if and if only the time ... More
Evolution of correlated multiplexity through stability maximizationApr 26 2016Investigating relation between various structural patterns found in real-world networks and stability of underlying systems is crucial to understand importance and evolutionary origin of such patterns. We evolve multiplex networks, comprising of anti-symmetric ... More
On the gravitational redshiftJul 01 2013Apr 16 2014The study of the gravitational redshift\,---\,a relative wavelength increase of $\approx 2 \times 10^{-6}$ was predicted for solar radiation by Einstein in 1908\,---\,is still an important subject in modern physics. In a dispute whether or not atom interferometry ... More
Impact models of gravitational and electrostatic forces: Potential energies, atomic clocks, gravitational anomalies and redshiftApr 10 2018The far-reaching gravitational force is described by a heuristic impact model with hypothetical massless entities propagating at the speed of light in vacuum and transferring momentum and energy be- tween massive bodies through interactions on a local ... More
Emergence of clustering: Role of inhibitionMay 10 2014Sep 19 2014Though biological and artificial complex systems having inhibitory connections exhibit high degree of clustering in their interaction pattern, the evolutionary origin of clustering in such systems remains a challenging problem. Using genetic algorithm ... More
A convex pseudo-likelihood framework for high dimensional partial correlation estimation with convergence guaranteesJul 20 2013Aug 14 2014Sparse high dimensional graphical model selection is a topic of much interest in modern day statistics. A popular approach is to apply l1-penalties to either (1) parametric likelihoods, or, (2) regularized regression/pseudo-likelihoods, with the latter ... More
Rejoinder: Gibbs Sampling, Exponential Families and Orthogonal PolynomialsAug 28 2008We are thankful to the discussants for their hard, interesting work. The main purpose of our paper was to give reasonably sharp rates of convergence for some simple examples of the Gibbs sampler. We chose examples from expository accounts where direct ... More
Posterior Graph Selection and Estimation Consistency for High-dimensional Bayesian DAG ModelsNov 03 2016Covariance estimation and selection for high-dimensional multivariate datasets is a fundamental problem in modern statistics. Gaussian directed acyclic graph (DAG) models are a popular class of models used for this purpose. Gaussian DAG models introduce ... More
Estimating the spectral gap of a trace-class Markov operatorApr 04 2017Apr 04 2019The utility of a Markov chain Monte Carlo algorithm is, in large part, determined by the size of the spectral gap of the corresponding Markov operator. However, calculating (and even approximating) the spectral gaps of practical Monte Carlo Markov chains ... More
High-dimensional posterior consistency for hierarchical non-local priors in regressionSep 19 2017Feb 22 2019The choice of tuning parameters in Bayesian variable selection is a critical problem in modern statistics. In particular, for Bayesian linear regression with non-local priors, the scale parameter in the non-local prior density is an important tuning parameter ... More
Posterior Graph Selection and Estimation Consistency for High-dimensional Bayesian DAG ModelsNov 03 2016Oct 11 2017Covariance estimation and selection for high-dimensional multivariate datasets is a fundamental problem in modern statistics. Gaussian directed acyclic graph (DAG) models are a popular class of models used for this purpose. Gaussian DAG models introduce ... More
Gibbs Sampling, Exponential Families and Orthogonal PolynomialsAug 28 2008We give families of examples where sharp rates of convergence to stationarity of the widely used Gibbs sampler are available. The examples involve standard exponential families and their conjugate priors. In each case, the transition operator is explicitly ... More
Active Imitation Learning via Reduction to I.I.D. Active LearningOct 16 2012In standard passive imitation learning, the goal is to learn a target policy by passively observing full execution trajectories of it. Unfortunately, generating such trajectories can require substantial expert effort and be impractical in some cases. ... More
A Bayesian Approach to Joint Estimation of Multiple Graphical ModelsFeb 10 2019The problem of joint estimation of multiple graphical models from high dimensional data has been studied in the statistics and machine learning literature, due to its importance in diverse fields including molecular biology, neuroscience and the social ... More
IR-UWB Detection and Fusion Strategies using Multiple Detector TypesJan 02 2015Mar 01 2016Optimal detection of ultra wideband (UWB) pulses in a UWB transceiver employing multiple detector types is proposed and analyzed in this paper. We propose several fusion techniques for fusing decisions made by individual IR-UWB detectors. We assess the ... More
Spectroscopic Diagnostics of Polar Coronal PlumesFeb 24 2009Feb 25 2009Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these observations, especially ... More
Dispersion Relation for MHD Waves in Homogeneous PlasmaNov 08 2006Jun 22 2007We consider viscosity and thermal conductivity as dissipation mechanisms to derive a general dispersion relation for MHD waves propagating in a homogeneous plasma. We show that the actual dispersion relation for MHD waves in a homogeneous medium must ... More
Colossal enhancement of electrical conductivity in Y2Ir2O7 nanoparticlesNov 17 2016We present a comparative study of the magnetic and electrical properties of polycrystalline and nanocrystalline Y2Ir2O7, the latter prepared using a new chemical route. We find that reduction in particle size leads to enhanced ferromagnetism and orders ... More
Comments on 'Controversy on a Dispersion Relation for MHD Waves' by Chandra and KumthekarSep 01 2007We comment on the work by Chandra and Kumthekar (2007, henceforth CK) which is questionable. In the derivation of dispersion relation, CK neither invoke the concept of vector space nor do they follow the basic criterion for the elimination of perturbation ... More
Optimization of synchronizability in multiplex networksJul 07 2015Feb 25 2016We investigate the optimization of synchronizability in multiplex networks and demonstrate that the interlayer coupling strength is the deciding factor for the efficiency of optimization. The optimized networks have homogeneity in the degree as well as ... More
Exploring anomalous $hb\bar b$ and $h b\bar bγ$ couplings in the context of the LHC and an $e^+e^-$ colliderFeb 20 2017Jul 29 2017In the light of the 125 GeV Higgs ($h$) discovery at the Large Hadron Collider (LHC), one of the primary goals of the LHC and possible future colliders is to understand its interactions more precisely. Here we have studied the $h$-$b$-$\bar b$-$\gamma$ ... More
Non-conventional porous 12CaO7Al2O3 Transparent Oxide Semiconductor: A Journey from foams to cubesJan 25 2017In the current study easy method to synthesize C12A7 particles with cubic morphology was investigated for the application of Transparent Conducting Oxide layer in thinfilm solar cell. By self-combustion method with proper amount of urea addition, cubic ... More
Initial data and the end state of spherically symmetric gravitational collapseApr 28 1998Generalizing earlier results on the initial data and the final fate of dust collapse, we study here the relevance of the initial state of a spherically symmetric matter cloud towards determining its end state in the course of a continuing gravitational ... More
Magnetostatics and the electric impact modelSep 30 2013Oct 20 2016The action of certain static magnetic fields on charged test particles is interpreted as a consequence of the interaction of the particles with electric dipole distributions emitted by other charged particles in relative motion. The dipole model of electric ... More
Comments on Viscous Damping of Non-Adiabatic MHD Waves in an Unbounded Solar Coronal Plasma by Kumar and KumarNov 08 2006Jun 22 2007Considering thermal conduction, compressive viscosity and optically thin radiation as damping mechanisms for MHD waves, we derive a six-order general dispersion relation. We point out a fundamental flaw in the derivation of five-order dispersion relation ... More
Multi Detector Fusion of Dynamic TOA Estimation using Kalman FilterJan 02 2015In this paper, we propose fusion of dynamic TOA (time of arrival) from multiple non-coherent detectors like energy detectors operating at sub-Nyquist rate through Kalman filtering. We also show that by using multiple of these energy detectors, we can ... More
Efficiently factoring polynomials modulo $p^4$Jan 20 2019Polynomial factoring has famous practical algorithms over fields-- finite, rational \& $p$-adic. However, modulo prime powers it gets hard as there is non-unique factorization and a combinatorial blowup ensues. For example, $x^2+p \bmod p^2$ is irreducible, ... More
Depletion of energy from Naked Singular regions during gravitational collapseApr 18 2010Jun 07 2011A distinguishable and observable physical property of Naked Singular Regions of the spacetime formed during a gravitational collapse has important implications for both experimental and theoretical relativity. We examine here whether energy can escape ... More
Initial Data and the Final Fate of Inhomogeneous Dust CollapseDec 10 1996We examine here the relevance of the initial state of a collapsing dust cloud towards determining it's final fate in the course of a continuing gravitational collapse. It is shown that given any arbitrary matter distribution $M(r)$ for the cloud at the ... More
Naked Singularities in Spherically Symmetric Inhomogeneous Tolman-Bondi Dust Cloud CollapseMar 31 1993We investigate the occurrence and nature of naked singularity for the inhomogeneous gravitational collapse of Tolman-Bondi dust clouds.It is shown that the naked singularities form at the center of the collapsing cloud in a wide class of collapse models ... More
Close Clustering Based Automated Color Image AnnotationAug 02 2010Most image-search approaches today are based on the text based tags associated with the images which are mostly human generated and are subject to various kinds of errors. The results of a query to the image database thus can often be misleading and may ... More
A gradient flow of isometric $\mathrm{G}_2$ structuresApr 22 2019May 08 2019We study a flow of $G_2$ structures which induce the same Riemannian metric which is the negative gradient flow of an energy functional. We prove Shi-type estimates for the torsion tensor along the flow. We show that at a finite-time singularity the torsion ... More
Wigner translations and the observer-dependence of the position of masslesss spinning particlesJan 19 2015The Wigner little group for massless particles is isomorphic to the Euclidean group ${\rm SE}(2)$. Applied to momentum eigenstates, or to infinite plane waves, the Euclidean "Wigner translations" act as the identity. We show that when applied to finite ... More
Modelling correlated marker effects in genome-wide prediction via Gaussian concentration graph modelsNov 10 2016In genome-wide prediction, independence of marker allele substitution effects is typically assumed; however, since early stages of this technology it has been known that nature points to correlated effects. In statistics, graphical models have been identified ... More
BIBI: Bayesian Inference of Breed CompositionApr 17 2017Sep 26 2017The aim of this paper was to develop statistical models to estimate individual breed composition based on the previously proposed idea of regressing discrete random variables corresponding to counts of reference alleles of biallelic molecular markers ... More
Generalized Pseudolikelihood Methods for Inverse Covariance EstimationMay 31 2016Oct 14 2016We introduce PseudoNet, a new pseudolikelihood-based estimator of the inverse covariance matrix, that has a number of useful statistical and computational properties. We show, through detailed experiments with synthetic and also real-world finance as ... More
Convergence Analysis of the Data Augmentation Algorithm for Bayesian Linear Regression with Non-Gaussian ErrorsJun 09 2015Jan 27 2016Gaussian errors are sometimes inappropriate in a multivariate linear regression setting because, for example, the data contain outliers. In such situations, it is often assumed that the error density is a scale mixture of multivariate normal densities ... More
ViTa-SLAM: Biologically-Inspired Visuo-Tactile SLAMApr 11 2019May 14 2019In this work, we propose a novel, bio-inspired multi-sensory SLAM approach called ViTa-SLAM. Compared to other multisensory SLAM variants, this approach allows for a seamless multi-sensory information fusion whilst naturally interacting with the environment. ... More
A Hybrid Alternative to Gibbs Sampling for Bayesian Latent Variable ModelsAug 27 2018Gibbs sampling is a widely popular Markov chain Monte Carlo algorithm which is often used to analyze intractable posterior distributions associated with Bayesian hierarchical models. The goal of this article is to introduce an alternative to Gibbs sampling ... More
ViTa-SLAM: Biologically-Inspired Visuo-Tactile SLAMApr 11 2019May 13 2019In this work, we propose a novel, bio-inspired multi-sensory SLAM approach called ViTa-SLAM. Compared to other multisensory SLAM variants, this approach allows for a seamless multi-sensory information fusion whilst naturally interacting with the environment. ... More
Inferring the Partial Correlation Structure of Allelic Effects and Incorporating it in Genome-wide PredictionMay 04 2017In this study, we addressed the problem of genome-wide prediction accounting for partial correlation of marker effects when the partial correlation structure, or equivalently, the pattern of zeros of the precision matrix is unknown. This problem requires ... More
Modelling correlated marker effects in genome-wide prediction via Gaussian concentration graph modelsNov 10 2016Sep 20 2017In genome-wide prediction, independence of marker allele substitution effects is typically assumed; however, since early stages of this technology it has been known that nature points to correlated effects. In statistics, graphical models have been identified ... More
Minimum Shared-Power Edge CutJun 12 2018We introduce a problem called the Minimum Shared-Power Edge Cut (MSPEC). The input to the problem is an undirected edge-weighted graph with distinguished vertices s and t, and the goal is to find an s-t cut by assigning "powers" at the vertices and removing ... More
Surface Wave Propagation in non--ideal plasmasJan 19 2015The properties of surface waves in a partially ionized, compressible magnetized plasma slab are investigated in this work. The waves are affected by the nonideal magnetohydrodynamic effects which causes finite drift of the magnetic field in the medium. ... More
Automated Remote Patient Monitoring: Data Sharing and Privacy Using BlockchainOct 30 2018The revolution of Internet of Things (IoT) devices and wearable technology has opened up great possibilities in remote patient monitoring. To streamline the diagnosis and treatment process, healthcare professionals are now adopting the wearable technology. ... More
The Structure of Naked Singularity in Self-similar Gravitational Collapse IIFeb 09 1993Generalizing the results of Joshi and Dwivedi in Commun.Math.Phys. 146, p.333 (1992), it is pointed out that strong curvature naked singularities could occur in the self-similar gravitational collapse of any form of matter satisfying the weak energy condition ... More
Mobile Database System: Role of Mobility on the Query ProcessingApr 10 2010The rapidly expanding technology of mobile communication will give mobile users capability of accessing information from anywhere and any time. The wireless technology has made it possible to achieve continuous connectivity in mobile environment. When ... More
On the bifurcation for fractional Laplace equationsJun 14 2016In this paper, we consider the bifurcation problem for fractional Laplace equation \begin{eqnarray*} \begin{array}{ll} (-\Delta)^{s} u = \lambda u + f(\lambda,\,x,\,u)& \mbox{in }\Omega, u = 0 &\mbox{in }\mathbb{R}^n\backslash \Omega, \end{array} \end{eqnarray*} ... More